Combined police-telephone circuit and gas-lighting apparatus



g i X N a1; Q i G. D. BANGROFT.

Combined Police Telephone Circuit and GasLighti'ng Apparatus. No. 240,804. Fgaten ted May 3, I881 X i W WITNESSES INVEN U N: FETUS, PHOTO-LITHUGRAFHER, WASHINGTON. D. C:

To all whom it may concern:

-UNITED STATES PATENT OFFICE.

GEORGE 1). BANUROFT, or BOSTON, MASSACHUSETTS.

COlVtBlNED POLICE-TELEPHONE CIRCUIT AND GAS-LIGHTING APPARATUS.

SPECIFICATION formingpart of Letters Patent No. 240,804, dated .May 3, 1881.

Application filed March 7, 1881. (No model.) i

Be it known that I, GEORGE D. BANGROFT, of Boston, in the State of Massachusetts. have invented an lnngrovement in Combined Police Telephone Circuits and Gas-Lighting Apparatus, of which the following is a specification.

The invention consists, first, in the combination, with a single main wire, of a telephonecircuit containing two or more telephones provided with an independent source or independent sources of electricity, and each telephone having an independent switch, by which it may be brought upon or disconnected from the main line; a gas-lighting circuit containing several burners, at each of which are an electro-magnet for controlling the cock and a wire for lighting the gas, both in the main line, and a suitable battery or magneto-machine provided with means for. coming upon the main line to operate the cooks and light the gas at the burners; and, second, in the t'urther combination therewith of an alarm-circuit with an independentbattery.

One of the telephones isat a central oftice. The others are at out-stations, in this specification termed watch-stations, and should be keptunder lock and key.

In the drawings I have illustrated the manner in which two gas-burners and a single watch-station may be worked in connection with a central office, and from the description it will appear that in the same manner any number of telephones and burners may be so worked.

Figure l is a diagram illustrating the combined systems. Fig. 2 is a cross-section of a commutator at a watch-station, taken 011 line as m, Fig. 1. i

The two burners are marked B and B They are both lighted at the same instant by the incandescence of platinum wires 1) 19 these wires being in the main line, which is elsewhere marked 1. Similar electrical apparatusis used at both burners, and it is necessary to describe that at one burner only; but for convenience in tracing the circuits the apparatus at both has been lettered, the numeral of theburner being added to the letters.

Confining this part of the description to the apparatus at burner B, E is an electro-magnet, and a its armature carrying a small pin,

which, when the armature is up, takes into a notch at one side or the other of a sector, I), rigidly secured to the gas-cock,

S is a thermosprin g connected with the sector b, as shown, and at the temperature of the atmosphere pressing inward to open the cook; but when heated by the gas'flamc pressing outward to close the cock, substantially as in patents heretofore granted to me. A current sufficiently strong to cause the electromagnet to attract its armature will heat the platinum i wirep sufficiently to light the gas. 1t follows that all the burners may be simultaneously lighted by sending a sufficiently strong current over the line, and also that when the gas has been burning long enoughto requisitely heat the thermo-springs it may be turned on simultaneously at all the burners by a similar current. To generate the current I employ a magneto-machine. (Shown at M.)

The telephone at the central offi'ce is marked T, the one at the watch-station is marked T. The telephone at the watch-station is normally I hung upon a hook in the end of a pivoted lever,

L, the weight of the telephone overpowering a spring, (1. The lever L, near its free end,

which carries the hook, is provided above and below with insulating-plates e e, the plate 6 carrying two metallic blocks, m m, to which are .securedrby binding-screws, the wires of the telephoneT, while beneath the insulatingplate a is secured a singlemetallic plate, a.

D 1) are two bridge-pieces, with the lower or upper projections of which the plate at or the blocks on m are in contact, accordingly as the telephone is on or off of its book.

The parts just described form a commutator, and itis obvious that the telephone T i is in the main line only when removed from the hook, and also that the'circuit is not broken in the commutator whcnthe telephone hangs upon the hook. i J

G, G G G andG are grounds, whose uses will appear in the description of the mode of operation hereinafter set forth.

H is a board provided with a switch,J ,v and two stops, b b, the switch J being normally in contact with stop I) by the force of the spring f secured to the board H. Stopb is in con tact with wire w, leading through the magneto-machine' M to ground at G. Stop b is in contact with Wire 20 leading to the alarm and telephone apparatus at the central-office, as will be described. Switch J is always in contact with line-wire l. It carries a piece of hard rubber, p, which, when the switch is in contact with stop I), strikes against a second spring, g, upon the board H. The arrangement is such that when the switch J is in its normal position, in contact with stop 1), contact is broken between stop 7/ and spring g; but when the switch is shifted to stop 0 contact is made between spring g and stop be fore it is broken between switch J and stop I). Spring g is connected by wire 20 with ground at G At the central oftlce are two other stops, 1 l, the latter of which is also a binding-screw, to which, with b another binding-screw, are connected the wires of the telephone T. A wire, 'w leads from stop l through a bell-m net, E and a battery, as shown, to ground at G while a wire, it), leads from binding-screw b to ground at G A spring, h, is so located as to be in contact with stop L when the telephone T is hung upon an arm projecting from said spring, and to be in contact with stop or binding-screw l when the telephone is removed from the arm.

R is the bell at the central otfice. Its hammer U is pivoted, as shown, and in its normal position is held up by the magnet E.

The line-wire l finds ground at G beyond the most remote burner or watch-station.

At Fig. 1 the apparatus is represented in its normal condition.

Themodes of operation and the circuits are as follows:

To call the central oflieefloni a watch-stati0n.The normal circuit is from ground G, by line-wire I, through the electric apparatus at burner B to bridge-piece D, plate n, bridgepiece D, to line-wirel again; then through the electric apparatus of the burner B to switch J; thence by stop 0 wire 20 to spring h, stop l wire 20, through bell-magnet E and battery to ground at G. The person having the key to the watch-box opens it and takes the telephone T from its hook. The lever L flies up and momentarily breaks the circuit, thus releasing the bellhammer U and ringing the bell R. The officer on duty at the central office then takes his telephone Tfrom its hook and the springh shifts from stop l to stop l In the meantime the circuit has been restored at the watch-box through the telephone T, and it may now easily be traced in the diagram from G to G 2. To restore the normal poliee-eirenit-The person at the watch-box and the operator at the central office hang up their respective telephones, and the latter lifts the bell-tongue U to its former position.

3. To light or extinguish the gem-The operator moves switch J from stop I) to stop b and generates acurrent in the magneto-machine M. The gas-lighting circuit is from ground G to switch J, as before, but is now from switch J through stop b wire to, and the magneto-machine M to ground at G 4. To lreep the alarnt-bellfrom ringing when lighting or extinguishing the gas.As before stated, the springgmakes contact with stop If before switch J breaks contact with that stop. When, therefore, a movement of the switch J would otherwise break the alarm-circuit by leaving stop the alarm-circuit gets a new ground at G and the hell does not ring.

I claim 1. In combination with a single line-wire, two electric circuits, neither normally established, the one a telephone-circuit containing two or more telephones provided with an illdependent source of electricity and brought upon theline, each telephone byits own switch, and the other a gas-lighting circuit containing several burners, each of which is furnished with an electro-magnetcontrolling its cock and a wire for lighting the gas, both in the main line, the gas-lighting circuit provided also with a battery or magnetomachine of requisite strength, and means for bringi n gthc same upon the main line, substantially as described, for the purpose specified.

2. A central telephone otlice furnished with an alarm-bell having an independent battery of interior strength,in combination with a single line-wire, a telephone-circuit, and a gaslighting circuit, neither of the latter normally established, but each provided with an independent source of electricity, and an independent switching mechanism for bringing it upon to.)

the main line, while the alarm-bell is always in its independent battery-circuit, which is broken when a telephone is brought upon the line, and is short-circuited when the gas-lighting circuitis established, substantially as de- 105 scribed.

GEORGE l). BANOROFT.

Witnesses SAML. V. BATES, W. P. PREBLE, Jr. 

